This invention relates to an exhaust gas re-circulation (EGR) tube that includes a dual seal assembly.
EGR tubes are used to re-circulate exhaust gases from the engine cylinders back into an intake manifold. The intake manifold is traditionally directly mounted, as an exposed component, to the engine for directing airflow into the engine. To facilitate assembly of the intake manifold and other associated components to the engine, it is desirable to have a more modular design that can be quickly and efficiently mounted to the engine. The modular design provides a housing that encloses the intake manifold and associated components. The housing and intake manifold components are pre-assembled and then are mounted to the engine as a unit.
An EGR tube has a first end in communication with an exhaust gas source and a second end in communication with the intake manifold. As the exhaust gases are transferred through the tube to the intake manifold, leakages can occur. Clean air from the external atmosphere can leak into the tube and/or the exhaust gases can leak out of the tube prior to being transferred back into the intake manifold. Either type of leak decreases the overall engine performance.
Traditionally, a single seal has been used to seal the tube to the intake manifold. This seal has not been effective in eliminating both types of EGR tube leaks in a configuration where the intake manifold is enclosed within a housing. Thus, it is desirable to have an improved sealing system to prevent clean air from leaking into the tube and to prevent exhaust gases from leaking out of the tube prior to entry into the intake manifold.